Depends what you need a surveyor for - if you want a surveyor for mortgage purposes, Colleys are good - they operate three levels of valuations/surveys at a fixed price. David Chapman is their SE1 surveyor and knows the area like the back of his hand and so very good on market knowledge and valuations. I don't know how good they are for more complex building/structural issues.
If you meant Civil/Structural Engineer, we used Richard Watkins of Lower Marsh, http://www.rwalondon.co.uk/about.html
for our flat refurb. Chose them randomly as they were local and granted it was 6 years ago but I recall they were practical and helpful.